HexApplet
The Hex Editor applet is a simple tool for exploring the CPU's memory.
After entering through the Submenu, the screen will display
80004255, indicating that the value at address 0x8000 is 0x4255.
Pressing 7, 8, 9, or / will increment a nybble of the address,
while the bottom row of buttons will decrement the same nybble.
Pressing 4 will disassemble the target address, showing us that
0x4255 means mov r2, r5.
The hex editor unlocks the ROM bootloader, which can be found at
0x1000. It blacklists a small undocumented range from 0x1b00, as
fetches from that region will reboot the CC420F6137.
The disassembler was rather hastily written and might contain bugs.
You can find it as libs/assembler.c, and it compiles to run in Unix
for testing.